Hydraulic motor control means



Original Filed Sept. l5, 1930 3 Sheets-Sheet l Qttomsy.

Sept. lo, 1935. w ERNST Re. 19,694

HYDRAULIC MOTOR CONTROL MEANS Original Filed Sept. 15. 1930 3 Sheets-Sheet 2 N Sw L TMQLL ""1 l l l I I n W` ERNST HYDRAULIC MOTOR CONTROL MEANS Original Filed Sapt. 15, 1930 3 Sheets-Sheet I5 Inventor, mfl'f'm a mtonnqs Sept. 10, 1935.

Ressued Sept.

1 19,894 masonic Moron coNrnoL MEANS- Walter Ernst, Mount Gilead, Ubin, assigner to This invention relates to hydraulic motor con- Y trol means and more "'he 4 Press Mount Gilead. Ohio original No. issus-tama Septem Serial No. 482,094, cation for 148,138

Manufacturing Company,

septmber' 19, 193s, her 15, 1930. Applirelsue october 12, i934, Serial No.

es cham. (ci. eso-sz) particularly to improvements in control means which are adapted for vuse in connection with kinds having reciprocating, double-acting such for example as hydraulic presses.

elements,

It is frequently desirable of the reciprocating means adapted to so fluid to the several motor as to cause the complete working stroke.

the end of initial or starting position and cally reversed at then return to its there be brought to hydraulic motors of various work that hydraulic motors type be control the iiow of pressure pressure chambers of the work element to perform a to then be automatithe working stroke, to

rest. Thissequenee of movements of the working element constitutes what is known in the arl: as and will be hereinafter semi-automatic" operation referred to as such. For

a completeunderstanding of an eillcient control mechanism arranged platen ofv a hydraulic press rquence, reference may be No. 1,711,318, granted April shown. described and Vclaimed nismincluding means responsive to sure in the pressing cylinder for automati to effect movements of the in the foregoing sehad to my prior Patent 30, 1929, in which is a control mecha-- reversing the direction of platen travel when the platen has completed the pressing operation,

and'

platen actuated means for automatically bringing the platen to rest at the end of each return stroke.

In my Patent No. 1,146,419 granted ilebruar'y l1, 1930 there is shown, described and claimed a control mechanism for hydraulic presses including 4means responsive tothe pressure in the pressstroke, and platen cally reversing the ing cylinder for automatically reversing the direction of 'platen travel actuated means for automatiat the end of each pressing direction of platen travel at the end oi each return stroke, so that the platen automatically performs an indeterminate number of pressing and return strokes.

This sequence 4of movements of the platen or work element constitutes what is known in automatic" operation and ferred to as such.

the art` as "completely will hereinafter be re- In some cases hydraulic motors are called upon to perform under either semi-automatic operation or completely automatic operation, depending upon the nature of the particular work to be done, and it is therefore desirable that the means controlling the movements oi' the work element be adapted for either semi-automatic or completely automatic .operation The control means disclosed ferred to above may in my prior Patent No. 1,746,419 rebe readily' arranged for either provided with control built-up presk valve being shown kind of operation with only a brief suspension of the operation of the press; but experience has demonstrated that it would be to advantage to provides. control means capable of being instantaneously adapted fior either semi-automatic or completely automatic operation without any interruption of operation.

It is accordingly an object-of the present invention toy provide a control means for hydraulic motors of the reciprocating double-acting type, including a single element which is adjustable to adapt the control means to eiect either semiautomatic or completely automatic operation of themotor.

Among the objects of the invention are to provide electrical control means capable of being nicely adjusted to effect accurate regulation oi' the travel of the work element and of the pressure attained during a working stroke. and to provide control means including a single element `which is selectively 'adjustable to adapt said means for automatically reversing the travel of the work element at the end of a working stroke either upon the attainment of a`predetermned pressure in the work cylinder, or upon the movable work elemehts reaching a predetermined position.

In the? drawings:

Figure l is a view in front elevation of hydraulic motor and control means embodying the invention, a`reversing valve being shown in vertical section;` l

Figure 2 is a fragmentary side elevation of the motor and control means shown in Figure l;

Figure 3 is a fragmentary horizontal sectional view taken on the line I-l of Figure 2;

Figure 4 isa detail vertical sectional vierw taken on the line 4-4 of Figure 3;

Figure 5 ls a detail sectional ing valve, a piston valve being shown in position from that shown in Figure l;

Figure 6 is a View similar to Figure 5, the piston in still another position; and

'Flgure'lisadiagrammatic showing of anelectrlcal control circuit. and

Figure 8 is a view partly in elevation of a modication in discharge pump is employed. f

The invention may be embodied in various kinds of hydraulic motors; but for the purposes of m illustration is shown as embodied in a hydraulic Apress A of the downward pressure type having a view of the reversa different section and partly in which areversible base I. a head 2 connected to the base by means spect to the base and the head. For reciprocating the platen there are provided cylinder means including a main or pressing cylinder 6 having a work chamber 1 and push-back cylinders 8 having return chambers l, and ram means connected to the platen and including a. pressing ram I0 mounted for reciprocation in the pressing cylinder, and return rams II mounted for reciprocation in the push-back cylinders 8.

For supplying fluid under pressure to the work chamber and to the return chamber to reciprocate the platen I provide a pump B, a tank or reservoir C, a reversing valve D, and suitable piping forming with the work and return chambers, the pump, the tank, and the valve, a reversible flow hydraulic circuit.

The valve D includes a 'casing l2 formed with a valve chamber I3, and a piston valve Il mounted for sliding movements within the casing. The piston valve comprises spaced heads I5, I6 and II, a valve stem I8 interposed between and connecting the heads I5 and I6, and a stem I9 interposed between and connecting the heads I6 and I'I. A passage 2U formed within the piston valve provides constant communication between the space dened by the valve casing and the heads I5 and I 6 and the space deined by the valve casing and the heads I 6 and I'I. A valve rod 2| extends from the head I5 through the adjacent end of the casing I2 for connection to valve actuating means to be later described.

The piping connecting the reversing valve, the tank and the pump to complete the reversible flow circuit includes a pump intake or suction pipe 22 respectively-communicating at its opposite ends with the pump and the tank, a. discharge pipe 23 communicating at one end with the pump and at its other end with the valve chamber I3, adjacent to the center thereof, a pipe 24 which connects the work chamber 'I of the main cylinder with the valve chamber at a point between the pipe 23 and the left hand end of the valve as viewed in Figures 1, 5 and 6, a pipe 25 which connects the return chambers 9 of the push-back cylinders with the valve chamber adjacent to the right hand end thereof, an exhaust pipe 26 connected to the tank C and exhaust branches 21, 28 and 29 respectively, communicating with the valve chamber, as shown in Figures 1, 5 and 6.

Thus far only the press and associated hydraulic circuit have been described and no means have been described for actuating the valve D to control the movements of the platen. In order to assist in the understanding of the detailed description of the control means which is to follow, the operation of the press will be brieiiy set forth without reference to any particular means for shifting the valve.

Assuming that the parts are in the relative positions shown in Figure l the pump will receive fluid through the suction pipe 22 and will discharge iluid under pressure through the pipe line 23 into that part of the valve chamber I3 then included between the valve heads I5 and I6. This fluid will thenpass through the passage 20 in the piston valve to the space between the valve heads Iiand IlandthencetotankCbymeansoIthe branch exhaast pipe 2l and the exhaust pipe 2li, the pump discharge being thus by-passed so as to produce no movement of the prem platen. Whenthepstonvalve Mismovedtoits extreme left hand position (the position' shown in Figureii), dischargetromthepmnpwill tlowthrough the discharge pipe 23 into that part of the valve ,L chamber then included between the heads I5 and ment of the platen and consequently of the pushback rams II forcing from the return chambers 9 the iluid which remained therein after the termination of the preceding return stroke. When' the working stroke has been completed, the valve Il will be moved to its extreme right hand position (the position shown in Figure 6), at which time the pump will deliver uid under pressure to the push-back cylinders by means of the discharge line then included between the heads I5 and I S, the passage 20 in the piston valve Il, that part of the valve chamber then included between the heads I6 and I1, and the pipe 25. Fluid under pressure thus delivered to the push-back cylinders will cause the platen to move upwardly which will result in expelling from the work chamber the huid remaining therein at the completion oi' the preceding working stroke, this fluid passing back to the tank through the pipe 24, that part of the valve chamber included between the head I5 and left hand end of the valve casing, the exhaust branch 21 and the exhaust pipe 26. When the platen has been thus returned to its uppermost position, the valve I may be moved either to its Figure 5 position to start another working stroke, or to its Figure l position to bring the platen to rest.

From the foregoing it will be observed that the valve Il is movable to three positions to respectively direct iiuid under pressure to the work chamber I to eilect a working stroke, or to the return chambers 8 to eiect areturn stroke, or to cutoff fluid iiow to both the work and return chambers simultaneously.

Although the invention is illustrated as being embodied in a press and associated hydraulic circuit including a pump of the constant delivery 23, that part of the valve chamber type, and a reversing valve for reversing the dlrection of uid travel in the circuit, it is obvious that the invention may also be embodied in hydraullc motors and associated circuits in which the pump is oi' the rotary, variable stroke, reversible discharge type and in which no separate reversing valve is used. Pumps of this type are 5,1

well known in the art and in general may be said to include a iloating ring adapted to be shifted oil? center in either of two directions with relation to other elements of the pump to eIIect discharge of fluid-under pressurel in either of two directions depending upon the direction in which the floating ring is shifted, or the ring may be moved to a central position relative to the other pump elements to reduce the pump discharge to zero. A pump of this type is fully disclosed in Patent No. 1,250,170 to Hele-Shaw et al., of December 18, 1917, and need not here be further described. For moving the valve Il from'either its Figure 1 or itsFIgurepositiontoitsFlgure position to effect a pressing Stroke of the platen, I have provided electrical valve-acmating means generally designated E and comprising a solenoid Il having a plunger 3l connected to the valve rod 2t through the medium of a linkin pivoted at its lowerendtothe'plunerl asatandplvoted the shaft I5. When the solenoid is in a manner to be hereinafter described, the plunger Il will be drawn downwardly which, ough the link 32 andthecrankarmwillrocktheshait- 3B in a clockwise direction. This rocking oi' the 'snm win swing the am u in a. clockwise direction and will move the valve rod 2l and the valve i4 to the left to their' Figure 5 positions. thus initiating a pressing stroke. It will be observed' that the solenoid 30 and valve D together constitute electrically actuated now-controlling means. Any other suitable form oirelectrical device having a movable element connected to the valve rod 2i' may be used instead oi the solenoid ill.

For constantly urging the valve I3 to its extreme right hand or Figure 6 position, there is provided a spring l2 interposed between a lug I3 on the press frame and an arm M secured to the shaft-I6, this spring tending t0 rotate the shaft 3G in a coimter-ciockwise direction. and

'to move the valve i4 to its Figure 6 position.

In accordance with the invention, control means are provided for either automatically energizing the solenoid when the platen approaches the end of a return stroke or for manuallyeiect ing'energizing oi.' the solenoid when the platen is at rest in its upper position; and for automatically eflectlng deenergizing of the solenoid when a predetermined degree of pressure is built up in the work chamber 1 during a pressing stroke, the deenergizing of the solenoid permitting the spring 42 to return the valve toits Figure 6 position to start a return stroke. This control means includes a rod l5 mounted for vertical sliding movements in lugs land 41 on the press head and base respectively, the rod 45 being urged downwardlyby means of a spring 4B in-` terposed between the lug 45' and a collar 48 se' cured to the rod, and being limited in its downward movement by a collar 56 secured to the rod and adapted to engage the lug I1. Mounted on the platen is an arm 5| having at its outer end a boss 52 through which the rod 45 extends and with respect to which the rod is freely slidable. During upward movement of the platen. the boss 52 is adapted to engage a collar 5l secured to the rod in adjusted position. After this engagement of the boss 52 with the collarv 53, further movement oi the'platen will raise the rod, and will move the valve il toward its Figure l position through medium of a forked arm 5l secured to the shaft 36 and engageable by a collar 55 secured to the rod`l5. When the rod is lifted the collar 55 will engage the arm. and will rock the latter in a clockwise direction, thus moving the valve il from its Figure 6 position to the left. As the platen approaches its uppermost position the valve Il will, by means oi the mechanism just described, be caused to gradually approach its Figure 1 position. During this movement of the valve, the head I8 will gradually uncover the exhaust branch pipe 2l so that the bypasstothetankwlllbegraduallyopcned. Atthe same time the head l1 will gradually cover the end o f the pipe l5. The return motion o! the platenwillceaseassoonasthethrottledexhaust opening between the valve chamber and theexhaustbranchllisenlargedtosuchadegreethatthepumppressurehssdromedtos valve to the weight oi the movsunnlv Y the movable press against the attraction of gravity. Although when the platen is automatically brought to rest in its upper position, the valuel Il will not be moved all thewaytothel'lgurefromthelligurelposition; itis obvious that in. the position to which the valve will be moved in actual practice, ow of iluid under pressure is eilectively cutoi! from both the work and-return chambers. A manually operable lever 5I secured to the shaft 3B provides for manual control oi the press whenever desired. The control rod I5 and 'the associated mechanism, it will be note'd. constitute ram-arresting means which is operable to bring the ram and platen to rest at the end oi' the return stroke.

VI n some cases, where the reversing valve is 20 necessarily heavy because of the high pressures handled, the force required to move the valve may be greater than that available from the solenoid 30 and the spring 42. In such cases the reversing valve may be actuated by eans ci an auxiliary hydraulic pilot circuit including a servomotor for Yeilecting the application or pressure to suitable pistons or plungers for moving the main valve' to eachoi' its three positions. Devices of this kind are well known in the art nd need not he here further referred to.

As previously stated, the invention may be embodied in hydraulic motorsand associated circuits in which the pump is of the rotary, reversible, discharge type in which no separate reversing valve is used. Figure 8 shows a pump B' of this kind adapted for connection to the hydraulic circuit shown in Flgurel and adapted to be controlled by the mechanism E. The pump B is of a'well known type including av casing 5ta-provided with combined inlet and outlet connections 55h and 56e connected respectively to the pipes 2l and 25, and a shiftable rod or ow 'controlling element idvplvoted as at 56e to the Anected across the pipes 24 and 25 and has its central chamber 55g connected to the tank c by means ofa pipe 56h for compensating for the unequal effective cross sectional areas of the cylinder 6 and the cylinders l in a manner well N understood in the art. It will be obvious that` the operationoi the ram may be controlled by shifting of'the pump rod 55d in the same way as by shiftingVv the valvel Il oi the arrangement shown in Figure i.

The solenoid 30 is adapted to be connected to a suitable source o! electrical power by means ci power lines 51' and 55; and a two-pole normally open main switch F which includes switch arms 59 and 0l adapted to be-,closed upon switch 7. points 8l and C2 to close the circuit through and to energize thesolenoid. 'The arms 5l and 5l oi' the main switch are fixed to a rotatable lshaft tiurgedinthedirectlonoi'thearmwzinngure'lbymeansolaspringttconnectedtom" partsin their upper position l4.5

ilaontheshafttheswlteharmsiland being thereby normally maintained out oi' It contaetwiththepointsllandl.

and a holding coil 1|, the latter when energiaedheinsptedtoattractanalmuxed totheshaftl asatlandtothus rotate the shaft .to close the main switch and to energize the solenoid. When the holding coil 1| is enemed the arm`12 will be swung in the direction of the arrow y (see Figure 7); at which time a normally open contactor switch G will beclosed, the switch G comprisinga contactorA bridge piece 'Il on the lower end of the arm 12 adapted to bridge two contact points `and 15,

thus connecting the circuit branch 65 with the conductor $9 and completing the pilot circuit.

through the branch i6. The shaft 93 and the arm 12 are urged to their Figura? positions by the spring 66. A

The circuit branch 95 includes apconductor 19 connected to the circuit portion BB, a normally closed emergency reverse pushbutton switch 89, a. conductor 8|, a conductor 82 connected to the contact point 15, and a double-throw switch 9.! having switch arms 84 and 85 adapted to close on a pair of switch points 86 and 81 or upon another pair oi switch points 88 and 89. When the switch arms are closed upon the points 86 and 91, the circuit branch 65 will be closed through a normally closed pressure responsive switch 90 connected across the points 88 and 81 of the switch 93; and when the arms of the switch 83 are closed upon the points 88 and 99, the circuit branch 65 will be closed through a normally closed platen operated switch 9| connected across the points 98 and B9 of the switch 83. The switch 9B includes a switch arm 92, springurged to its closed position and an operating arm i 93 mounted Yin xed relation to the switch arm 92. This switch is adapted to be open by,means y of a Vrod 94 mounted on a piston 95 arranged for sliding movements in a cylinder 96 mounted on the press head. The piston 95 and the rod 94 are urged to the left as viewed in Figure 1 by means of a spring 91 ton and a nut 9B by means of which the compression of spring 91 may be adjusted. The chamber within the cylinder 96 is in constant communication with Athe work chamber 1 through the medium of a pipe 99 so that the unit pressure within the cylinder 96 will always be equal to that in the work chamber. The compression of the spring 91 is so adjusted that the piston 95 will remain in its extreme left hand position as shown in Figure l until a desired predetermined pressure Y chamber and in the cylinder 96 during a working stroke, at which time the piston 95 and the rod 94 will be moved to the right against the action of the spring 91, the rod 94 at this time engaging the operating arm 93 oi' the switch 90 and moving it to rock the switch arm 92 in a platen-operated switch 9|.

interposed between the pishas built up in the work' clockwise man. nus, when the double throwmtehiscloduponthepointstandll-- and theswitch 99 thereby made part ofthe circuitbranehilopgningoftheswitchllseryes A. ,to breakthe pilot circuit through the' circuit 5 branch-II, thereby deenergizinglthe coil V1| and effecting openixg'of the main switchto also deenergiae the solenoid. This permits the spring Ittomnvethevalve MtoitsFigureposition and to start a return stroke of the platen.

Whenthe arms of the double pole switch B3 are closed upon the points B9 and Mythe 'circuit branch will be normally closed through the 'This switch includes a switch 'arm MII spring-urged to closed position and an operating arm ii mounted in ixed relation to the switch arm. 'Ihe switch 9| is adapted to be opened when the platen reaches a predetermined position during a pressing stroke by means of a collar |82hxed to a rod |03 mounted 20 for sliding movements in lugs |94 and |05 on the press head' and base respectively and being adapted to be moved downwardly through the medium of an ann |06 carried by the platen and having at its outer end a boss |91 through 25 which the rod extends, and a collar I 08 adjustably secured to the rod and adapted to be engaged by the boss |91 and moved downwardly against the urge of a spring |99 interposed between the upper face of the lug IM and a collar H0 on the rod. A collar HI is securedA to the rod and is engageable with the lower tace .oi' the lug |94 for limiting upward movement of the rod under the urge oi' tthe spring |99. Thus when the rod is moved downwardly the collar |52 will engage the operating arm IBI of the switch 9| therebyv opening the latter, breaking the pilot circuit through the circuit branch 65 and deenergizing the solenoid. As before stated, the deenergizing o1V the solenoid permits the spring 42 to return the valve 40 I4 to itsFigure 6 position to start a return stroke ot the' platen.

From the foregoing, it will be observed that through the selective setting or the double-throw switch 83 the control means is adapted for re 45 versai'oi the platen at the end oi' a pressing stroke either in accordance with the distance travelled by the platen, or the pressure exerted upon the Work.

It will be observed that when the holding coil 50 i 1| has been once energized and the bridge piece 14 closed upon the contact points 15 and 16 in the manner already described the pilot circuit will maintaining the coil 1| energizedand maintaining the bridge piece 14 closed upon the.points .15 and 16 until either the switch 80 or one or the other oi the switches 99 and 9| is opened.

The circuit branch B6 includes the conductor 19, 60 a normally open manually operable starter switch H2 preferably of the push-button varietyfand a conductor I3 connected to the common conductor 69. Assuming that all of the circuit branches are open as shown in Figure 7 and that it is desired to 65 momentarily manually energize the holding coil 1| to close the main switch and to close the bridge piece 'M upon the points 15 and lrthe pushbut @on switch H2 is pressed, thus closing uie pilot circuit through the common circuit portion .68, the conductor 19, the switch ||2\.'the.conductor |13 and the conductor 6,9. As soon holding coli switch ns is closed the closing operable resultant lowering of buttonswitchlllwillnotactto` the holding coil 1l or to open the main switch.

Whenitisdedredthat thepressoperateunder completely automatic control. it is necessary that means be provided for automatically eilecting Ia. closingoithe mainswitchtoenergise thesolenoid when the platen approaches the end oi' a return stroke.- The circuit branch t1 is adapted to automatically effect closing of the pilot circuit at this time and to this end includes a conductor I Il con-- nected to the common circuit portion il, a manuselector switch I I5, a conductor I IB, a normally open reversing switch II'I having a switch arm Ill springn'ged to open position, a conductor Il! and the conductor Ill. A collar operated rod l5 is A which as stated above, effects closing oi the main switch and energizing of the solenoid. When the platen begins another stroke with the the rod l5 and opening of the switch iI'I, the holding coil will maintain the bridge piece 1I closed upon the contact points 15 and 1G, thus maintaining the main switch F closed and the solenoid energized stroke has been completed and the switch 90 or the switch 9i opened in the manner already de- Y scribed.

It will be noted that throughthe closing or opening of the manually operable selector switch H5, the closing and opening of the switch II1 in f the circuit branch 61 will be rendered eiective or ineffective as desired, that is to say,l when the of the switch .I Il. will automatically eil'ect energizing of the .sola-n noid when the platen'approaches the end of aV return stroke, whereas when the switch H5 is open the closing oi the switch II! will be ineffective. The various electrical devices employed are oi well known standard types obtainable from electrical manufacturers, and lor'this reason, and in the interest oi simplicity and clearness of the disclosure. the details thereof have not been illustrated or described.

Operation In order that understood, the operation under both semi-automatic and completely automatic control will be described. It will be assumed that the parts are in the relative positions shown in Figs. l, 2, 3, 4, and "i and that the motor or other prime mover driving the pump B is in operation. As hereinbefore stated, with the parts in the positions shown in the ilgures referred to above, the discharge from pump will be by-passed to the tank C and no movement o( the platen 4 will take place. I! it is desired that the press be operated under fully automatic control, it is necessary as a preliminary step to close the manually operable selector switch H5 in the circuit branch 81.

g also, it is desired that the platen be re versed when a predetermined pressure -has been exerted on the work, irrespective of the distance travelled by the platen, the double pole switch!! will be closed upon the points ll and 81 to connect the pressure responsive switch lo in the circuit branch l. 'I'o initiate pressing movement oi the platen the push button starter switch il! isthen momentarily closed. gThis closes the pilot circuit position in the manner until the pressing.

, place in the manner already described.

the invention may be more clearly 1 the starter switch Il! in the through the conductor I. the circuit branchy It 'and the circuit portion Il, thus energizing the holdincoilli whichmovesthearmn toclosethe normallyopenswitchGandtoalsoclosethemainswitch r" The closing of the switch r' energize: the solenoid which acts to draw the plunger 3| down and to move the piston valve Il to its Fig. 5 already described. When the push button starter switch I II is again a1- lowed to open, the pilot circuit will remain closed through the circuit branch B5 and the solenoid will be maintained energized to retain the valve Id in its Fig. 5 position against the urge of the spring 42. With the valve in its Fig. 5 position pump discharge is directed to the work chamber oi the main cylinder `and the platen is moved downwardly to perform a pressing operation. As soon as sufdcient resistance is oil'ered by the work to the downward movement oi the platen, pressure will build up in the work chamber 1 to a degree sufil- 20 cient to move the piston 95 and the rod 9| to the right. Whenso moved the rod 94 will engage the operating arm S3 of the normally closed switch 9B and n the latter, thus breaking the pilot circuit,`deenergizing switch G and the switch F, and deenergizing the solenoid. The spring 42 will then move the piston valve I4 to its Fig. 6 position through the medium oi the arm M, the k shaft 35, the arm 4i, and the link 3,8. Pressure fluid will then be directed to the return chambers 9 oi the push back cylinders and will move the platen upwardly to perform a. return stroke. When the platen approaches the end of the return stroke the boss 52 carried by the platen .will engage the collar 53 on the rod 45, thereby lifting the rod and causing the collar IZG to engage and move the operating arrn I2I of the normally open switch l I1 to close the latter. This closing of the switch Ill will .complete the pilot circuit through the common The solenoid, having thus been energized, another 4 pressing stroke will begin and an indeterminate number of complete cycles of operations will take It will be noted that when the platen begins another pressing stroke andthe rod is lowered the switch III will be opened, thus breaking the circuit through the branch G1. However, the pilot circuit will still'be closed through the circuit branch B5 so that the solenoid will be maintained energized in the same manner as when the pilot circuit was through the-branch 6B when the momentarllyclose the switch III.

the holding coil 1 I, opening the 25 If it is desired that the press operate under semiu automaticcontrol theselector switch i i5 is opened. The operation will then/be started by closing circuit branch 55 in the manner already described in connection with the completely automatic operai-.ioni The platen will then perform a pressing stroke and will start a return stroke in the same manner as in completely automatic operation. However, when the platen approaches the end oi' the return stroke and.

the switch I I1 is closed through the raising of the rod 45, no closing oi the pilot circuit will be effected since the previous opening of the selector switch II5 has rendered the closing o f the switch I I1 ineffective. The platen will therefore continue to move upwardly until the collar 55 on the rod l5 engages the forked lever 54 and rocks the shaft 3B in a clockwise direction suiilciexitly to move the piston valve I4 to its Figure 1 position or approximately to this position. In other words, as before stated, the valve Il will be moved to the lei' t until the head I 6 uncovers the exhaust branch 28 to such an extent, and the throttled exhaust opening between the valve chamber and the exhaust branch 2B is enlarged to such aAdegree that the pump pressure balance the weight A state of balance the pump will supply fluid at a pressure just sumcient to hold the movable press parts in their upper position. In order to cause the platen to per- .form another pressing andv return stroke the starter switch I after which the same sequence of movements of the platen will take place and the platen will again be brought to rest in its uppermost position.

It it be desired that, during either automatic ,or semi-automatic` operation, the platen be reversed when a predetermined position has been reached during the pressure exerted upon the work, the double pole switch 83 will be points 80 and 89 to connect the platen operated switch 9| in the circuit branch G5. Then, regardless of whether the press is arranged for automatic or for semi-automatic control, the opening o! the switch 9| caused by the downward movement of the rod i 03 elected by engagement of the boss IM on the platen with the collar I 08 on the rod will open the pilot circuit through the circuit branch 65, deenergize the solenoid and permit the spring 42 to return the valve I4 to its Fig. 6

of the movable press elements.

position.

If it is desired to reverse the direction of travel .l

oi' the platen at any time when it is performing a pressing stroke, whether under may be accomplished by opening the manually operable emergency reverse switch ll. This will break the pilot circuit through the branch B5 whereby the holding coil I'I will be and the switches G and F will be opened, thus deenergizing the solenoid and permitting the spring I2 to move the valve to its Fig. 6 position, where-V upon the platen will immediately approach its upper position and stroke or be brought to rest. depending upon whether the pilot circuit is adapted i'or fully automatic or semi-automatic control.

I1' the press be operating under fully automatic control and an emergency arises which is such that the platen should be prevented from starting downward from its circuit may be rendered inoperative by 1l. Aslong as this switch is open it will be impossible to start the press drops to the value required to' will then exist in the circuit and` I2 is again momentarily depressed a pressing stroke, irrespective of.

closed upon the contact semi-automatic or completely automatic/ operation, such reversal uppermost position, the pilot deenexgized again by means oi' the electrically actuated means.

although any desired movements o! platen may be eirected at any time by means of the manually operable lever 5i.

It will be observed that by closing or opening the selector switch H5 the closing of the platen operated switch II'I may be rendened eective or ineffective and that the switch IIS therefore con By means of my improved control apparatus. 5

accurate regulation of the extent of platen travel and oi' the working pressures exerted is attainof the simplicity of the pushemployed. less eifort on the part is required than'when using herecontrol means. These and other advantages result from the fact that the elecused are freely moving and work without appreciable mechanical Lriction, being either semi-automatic or completely automatic 20 operation by the selective setting of a single electric switch.

I claim:

completely or semi-automatic operation `oi' saidl 30 ram means, said control means including means selectively rendering or inactive. 1

2. 'I'he combination with a hydraulic motor'including cylinder means having a work chamber spectively direct uld from said pump to said work chamber. or to said return chamber, or to 5o cut oil iuid ow to both chambers simultanesaid valve means from its second to its third posi- 65 motor for either completely or semi-automatic operationI as desired.

3. The combination with a hydraulic motor an electric switch adapted I...

, return stroke;

including a cylinder means having a work chamber and a return chamber. and ram means mounted for reciprocatory movementsin said cylinder means; ot a pump; means formingwith positions to respectively direct iluid from said pump to said work chamben'or-to said return chamber, or to cut on' uid new to both chambers simultaneously; means for 'automatically moving said valve means iromdsltlrstto its second position at the end 'of a working stroke to start a adapted when active t automatically move said valve means from its second to its first position at the end of a return stroke to start another working stroke; independent meanseil'ectlve when said electrically actuated means is inactive to automatically move said valve means from its second to its third position atthe end of a return stroke to bring said ram means to rest: and a manually operable electric switch adapted to render said electrically actuated means active during a return stroke to eil'ect completely automatic operationci' `said motor, or to render said means inactive during a return stroke to eiect semi-automatic operation thereof.

4. I'he combination with a hydraulic motor including cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatory movements in said cylinder means; oi' a pump: means -forming with said pump and said chambers a hydraulic circuit; valve means in said circuit movable to three positions to respectively direct fluid from said pump to said work chamber, or to said return chamber, or to cut ott iiuid flow to both chambers simultaneously; means responsive to attainment of a predetermined pressure in said work chamber during a working stroke for automatically moving said valve means from its iirst to its second position to start a return stroke; electrically actuated means adapted when active to automatically move said valve means from its second ,to its first position at the end of a return stroke to start another working stroke; independent means operable by said ram means when the latter approaches the end oi' a return stroke and effective when said electrically actuated means is inactive to automatically move said valvemeans from its second to its third position to bring said ram means to rest; and a manually operableYV electric switch. adapted to render said electrically actuated means active during a return stroke to ei rect completely automatic operation oi said motor,

or to render said means inactive during a return,-

stroke to effect semi-automatic operation thereof.

5. The combination with a hydraulic motor including cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatory movements in said cylinder V means; oi a pump; meansiorming with said pump and said chambers a hydraulic circuit for delivering fluid under pressure to bothof said chambers; electrically actuated flow-'controlling means in said circuit for effecting delivery o! iiuid under pressure to said n bers separately; closed to Veiiect actuation or said flow controlling means; and means associated with said switch -and being responsive to a change in pressure in one oisaid chambers for operating said switch, the pressureoperated means being connected to an auxiliary circuit having a holding means for retaining said switchimone oi- Ils positions.

electrically actuated means .return trokes of said ram means; i electrical 6. The combination with a hydraulic motor including cylinder means having a work chamber and a return chamber, and'ram means mounted for reciprocatory movements in said cylinder said pump andsaidchambers a hydrauliccircuit: valve means in said circuit movable to three delivering duid under pressure to both of said chambers; flow controlling means in said circuit movable to two positions to direct-fluid from said p ump to said work chamber and to' saidfreturn 10 chamber respectively; electrical actuating .means associated with said flow-controlling means and adapted when active to move the latter to one of said positions; an electric switch having electrical connection with said actuating means;v means usl associated withl said switch and being responsive to the pressure in one of said chambers for operating said switch to render said electrical actuating means inactive; and means i'or then moving said iiow controlling means to its other position, 20 the pressure-operated meansbeing connected to an auxiliary circuit having a vholding means for retaining said switch in one o! its positions.

'L The combination with a hydraulic motor including cylinder means having a work chamber 25 and a return chamber, and ram means mounted for reciprocatory movements in said cylinder means; of a pump; means forming with said pump and said chambers a hydraulic circuit for delivering fluid under pressure to both of said 80 chambers; flow controlling means in said circuit `movable to two positions to direct fluid under pressure to said work chamber and to said return chamber respectively toeiiect working and actuating means connected toy said flow controlling means and adapted when active to move the latter to its rst position; and switch means for closing andopening anelectric circuit through said actuating means, said switch means being 40 operable by said ramgneans when the latter approaches the end oi' a return stroke (or rendering active said electrical actuating means, and

being responsive to pressure ln said work chamber when the ram means is performing a working i5 stroke for renderlngsaid actuating means inactive, the pressure-operated means being con-v nected to an auxiliary circuit having a holding means for retaining said switch means in one oi its positions. s 50 8. The combinationwith a hydraulic motor including cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatory movementsl in said cylinder means; of a pump: means forming with said pumpr and said chambers a hydraulicclrcuit Vfor delivering iiuid under pressure to both of said chambers; dow controlling means in said circuit movable to two positions to direct iiuid under pressure to said work chambers and to said return chamber respectively to effect workingand return strokes of said ram means; electrical actuating means connected to said flow controlling means and adapted when active to move the latter to itsiirst position; switch means for closing and opening an electric circuit through said actuating means, said switch means being operable by said ram means when the latter approaches the cnd of areturn stroke for rendering active said electrical actuating means, and being responsive to pressurein said work ,chamber when the ram means is performing a working stroke for rendering said actuating l means inactive; and means for then moving said -'Iii iiow controlling means to its second position. the pressure-operated means being connected to an auriliary circuit having a holding means for retaining said switch means in one oi its positions. e f

9. yThe combination with a hydraulic motor f including cylinder means having acwork chamher` and a return chamber. and ram means mounted for reclprocatorymovements in said cylinder means: of a pump; means forming with said pump and said chambers a hydraulic 'circuit for delivering fluid under pressure to both or said chambers; a valve in said `circuit movable to two positions to direct iluid from said pump to said work-chamber and to said return chamber respectively to eiiect working and return strokes of said ram means: an electrical device having a movable element connected to said valve and adapted when said device is energized, to movei said valve to its iii-st position; switch means for controlling the closing -and opening of an electric circuit through said devicelweaidswitch means being operable by said ram means. when the latter approaches theiend o i `a return stroke for closing said electric circuit to energize said device, and being responsive to an increase in pressure in said work chamber when the ram means is performing a working stroke for opening said electric circuit to deenergize said device, and a spring connected to said valve and urging the latter to itssecond position, the pressureoperated means being connected to an circuit having a holding means for retaining said switch means in one oi' its positions. y

10. 'I'hecomblnation with a hydraulic motor including cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatory movements in said cylinder means; of a pump; means forming with said pump and said chambers a hydraulic circuit; flow-'controlling means in said circuit movable to three positions to respectively direct iluid ,from said' pump to said work chamber. and to said return chamber, and to cut on' iluid ow to both chambers simultaneously; electrical actuating means connected to said now-controlling means and adapted when active to move the latter to its ilrst position; means for urging said ow-controiling means to its second position; means operable by said ram means when the latter approaches the end of a return stroke to move said flow-controlling means to its third position; and switch means for closing and opening an electric circuit through said actuating meanasaid switch means being manually operable to close said electric circuit to render said ber, and to cut oil iluid flow to both chambers simultaneously; an electrical device having a movable element connected to said valve and adapted when said device is energized to move the valve to its iirst position: a spring connected tosaidvalveandurglngthelattertoitssecond position: means operable by said ram means when the latter approaches the end oi a return stroke to move said valve to its third position: means for closing and opening an electric circuit through said device including a normally open switch adapted to be manually closed toA close said electric circuit and energize said device; and a normally closed switch adapted to open said electric circuit and deenerglze said device; and means responsive to a change in pressure in said work chamber for opening said normally closed switch.

' l2. The combination with a hydraulic motor including cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatorymovements in said cylinder means; oi a pump; means forming with said pump and said chambers a hydraulic circult; electrically actuated how-controlling means in said circuit for reversing the direction of ow therein: a main switch adapted to, close an electric circuit through rsalti flow-controlling means to eilect a reversal of fluid ilow; a pilot electric circuit including two parallel circuit branches; a normally open switch in the first branch adapted to be manually closed to close said pilot circuit; a normally open switch in kthe second branch; a holding coil in said pilot .circuit exterior oi' said branches and adapted when energized to close the normally open switch in said second branch and to close said main switch; a normally closed switch in said second branch; and means associated with said last named switch and responsive to a change in pressure in said work chamber for opening said switch.

13. The combination with a hydraulic motor including cylinder means having a, work chamber and a return chamber, and ram means mounted for reciprocatcry movements in said cylinder means; of a. pump; means forming with said pump and said chambers a hydraulic circuit; electrically actuated flow-controlling means in said'circuit for reversing the direction of4 ow therein; a main switch adapted to close an electric circuit through said flow-controlling means for actuating the latter; a pilot electric circuit including two parallel circuit branches; a normally open manually operable starter switch in the rst branch adapted to close said pilot circuit; a normally open switch in the second branch; a holding coil in said pilot circuitexte` rior of said branches and adapted when energized to close the normally open switch in said second branch and to close said main switch; a normally closed switch in said second branch adapted to be opened when pressure in said work chamber has built up to a predetermined value; and a normally closed manually operable emergency reverse switch in saidfsecond branch for opening said pilot circuit and `.thereby effecting opening of said main switch at any desired time when said pilot circuit is otherwise closed through said second branch.

14. The combination with a hydraulic motor including cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatory movements in said cylinder means; oi a pump; means forming with said pump and said chambers a hydraulic circuit; a valve in said circuit movable to two positions to respectively direct iiuid from said pump to said work chamber, and torsaid return chamber; an electrical device having a movable element connected to said valve and adapted when said deand with said pressure responsive switch ior selectively connecting either the ram-operated or the pressure responsive switch infcircuit with said flow controlling means.

19, The combination with a hydraulic motorV for presses or the like including reciprocable ram means; of means forming a hydraulic circuit with said motor for operating said ram means in both directions: andA control means associated with said circuit for controlling the direction oi' now therein and including means for efl'ecting automatic reversal oi' said ram means at the end oi' a pressing stroke, means including an electric switch automatically operable to eilect a reversal oi movement of said ram means at the endo! a return stroke' means operable by said ram means when the latter approaches the end oi said return stroke for bringing said ram means to rest; and a manually operable electric selector switch in circuit with said automatically' operable switch. and being movable to two positions to selectively adapt said control means i'or completely or for semi-automatic operation oi' said ram means.

20. The combination with a hydraulic motor including reciprocable ram means; o! means forming a hydraulic circuit with said motor for operating said ram means in both directions; and control means associated with said circuit lor controlling the direction of i'low therein and including electric switch means for automatically efl'ectingreversalof iiow of fluid at the end oi.'

a working stroke. fluid pressure responsive means for operating said switch means; means responsive to ram travel and independent of pressure for operating said switch-means; and means for selectively rendering either one of said switchoperating means effective, whereby said ram means may be automatically reversed l upon reaching a predetermined position during a working stroke or upon the building up of a predetermined pressure.

21. The combination with a hydraulic motor including reciprocable ram means; oi means forming a hydraulic circuit with said motor foi' operating said ram means in both directions; and control means associated with said' circuit for controlling the direction oi' flow therein and including a, pressure responsive electric switch for automatically effecting reversal oi i'iow of iiuid upon building up of apredetermined pressure during a working stroke. other means for automatically effecting reversal of ilow of fluid when the ram means reaches a predetermined position during a working stroke: and means for selectively rendering either one oi said last two elements singly eiiective whereby said ram means may be automatically reversed upon building upv ci a predetermined pressure during a working stroke or upon reaching a predetermined position during a working stroke.

22. The combination oi' a hydraulic motor including a reciprocable ram; of means for supplying fluid under pressure to the press for operating said ram; and control means associated with said press and circuit including means for controlling the flow of uid to said ram pressure responsive means for automatically eilecting discontinuance v of flow to said ram upon building up oi a predetermined 'pressure on said ram, position controlled means for automatically effecting discontinuance of iow to said ram upon the latter's reaching a predetermined' position during a' stroke, and` means for selectively rendering one only oi said last two elements eiective whereby the ram stroke may be automatically discontinued upon building up oi a'predetermined pressure during a stroke or upon the ram's reaching a predetermined position during a stroke. e

28. ,The combination of a hydraulic motor inn cluding a reciprocabie ram; oi' means for supplying iluld under pressure to the press for operating said ram: and control means associated with said press and circuit including means for controlling the tlow oi duid to said ram. a pressure 1() responsive electric switch for automaticallyy edecting discontinuance oi ow to said ram upon building up of a predetermined pressure on said ram. other means i'or automatically eiecting discontinuance ot ilow to said ram upon the 1g; latters reaching a predetermined position during a stroke, and means for selectively rendering either one oi saidlast two elements eifective whereby the ram stroke may be automatically, discontinued upon building up oi' a predetermined pressure during a stroke or upon the rams reaching a predetermined position during a stroke.

simultaneously; an electric switch adapted when operated to eilect actuation of said iiow controlling means: means associated with said switch and being responsive to the building up of a maxig5, mum predetermined pressure in said work chamber at the end of a working stroke of said ram means for operating said switch to eiect actuation of said ow controlling means and delivery of iluid under pressure to said return chamber; 40 and means for actuating said iiow controlling means when said ram means reaches the end of a return stroke for discontinuing delivery of iiuid to both chambers simultaneously to thereby bring said ram means to rest. 4&5

25. The combination with a hydraulic press including cylinder means having a work chamber and a return chamber. and ram means mounted tor reciprocatory movements in said cylinder means; oi' a pump: hydraulic connections between 50 said pump and both oi' said chambers; iiow controlling means for eiecting delivery oi iiuid under pressure separately to both chambers and for discontinuing delivery to both chambers simultaneously; an electric switch adapted when op- 55 erated to eilect actuatlon'of said ilow controlling means; means associated with 'said switch and being responsive-to the buildingup oi' a maximum predeterminedpressure in said work chamber at the end of svworkin'g stroke ci said ram 60 means for operating said switch to eiect actuation of said iiow controlling means and delivery of 'iluid under pressure to said lreturn chamber; and means connected to said flow controlling j means and being adapted to be engaged by said ram means when the latter approaches the end oi' a return stroke ior actuating said flow controlling'means for discontinuing delivery of iluid under pressure to both chambers simultaneously to thereby bringV said ram means to rest.

26. The combination with a hydraulic press in- .cluding cylinder means having a work chamber V means; of a plump;i hydraulic connections beigif tween said pump and both o! 4said chambers; viiow controlling means for delivery, ot iiuid under pressure separately to both chambers and for discontinuing delivery to bothchambers simultaneously; an electric switch adapted when-operated to eiect actuation oi'. said ;l'iow controlling means; means separate from said ilow controlling u ot the latter and delivery of huid under pressure,` to said return chamber; and means for actuatingl said iiow controlling means when said ram means reaches the end of a return stroke for discontinuing delivery o! iuid to Vboth chambers simul-4 taneously to thereby bring said ram means to rest.

having reciprocable ram' means; of means iorming a hydraulic circuit Vwith said motor for operating said ram means in both directions; and control means associated with said circuit for controlling the ilow of fluid thereinA to eect semiautomatic operation o! said ram means, said con- .trol means including electrically-operated pressure-responsive means for automatically reversincluding a reciprocable ram; of means ior supplying iluid under pressure to the motor for operating said ram; and control means associated with said motor including means i'or controlling the flow oi 'uld to said ram,'electricallyactuated 5 pressure-responsive means for automatically etthe latters reaching a predetermined positioning ing said ram means when Va working strokel'iasV been completed, and means responsive to travel of the ram means for automatically bringing the ram means to rest at the end of a return stroke. 28. The combination with a hydraulic motor having reciprocable ram means; of means forming a hydraulic circuit with said motor for operating said ram means in both directions; and control means associated with said circuit for controlling the flow oi fluid therein to eilect semi.- automatic operation of said ram means, said control means including electrically-operated pres'- sure-responsive means and electrically-operated position-responsive means selectively actuated for automatically reversing said ram means when a4 during the return stroke thereof.

32. I'he combination with a hydraulic press includinga cylinder means having a work chamber and a return chamber, and ram means mounted 15 for reciprocatory movements in said cylinder -means: ol'- a pump; 4flow-controlling means for effecting delivery of uid under pressure selec- A tively to either chamber; a pressure-responsive 27. The combination with a hydraulic motor electric switch adapted to be actuated upon the attainment of a maximum predetermined pressure in said work chamber; and devices adapted to be operated by the-actuation 'of said switch for divexting` said delivery of fluid under pressure from said working chamber' to said return chamber.

33. The combination with a hydraulic press lncluding a cylinder means having a work chamber and a return chamber, and ram means mounted for reciprocatory movements in said cylinder means; of a pump, flow-controlling means for ei'- iecting delivery oi fluid under pressure selectively to either chamber; a pressure-responsive electric switch adapted to be actuated upon the attainment ora maximum predetermined pressure in working stroke has been completed, and means responsive to travel of the ram means for automatically bringing the ram means to rest at the end of a return stroke.

29. The combination with a. hydraulic motor having reciprocable ram means; of means formtrolling the flow of fluid therein to effect semiautomatic operation of said ram means, said control means including electrically-operated pressure-responsive means for automatically reversing said ram means upon the attainment oi a predetermined pressure during the working stroke, and means for automatically bringing therein means to rest at the end of a return stroke. j

30. The combination with ahydraulic motor having reciprocable ram means; of means forming a hydraulic circuit with said motor for operating said ram means in both directions; and control means associated with said circuit forcontrolling the flow of fluid therein to effect semiautomatic operation of said ram means, said control means including electrically-operated pressure-responsive means i'or automatically reversing said ram means upon the attainment of a' predetermined pressure during the working stroke, and means responsive to travel of the ram means i'or automatically bringing the ram means to rest at the end ofa return stroke.

3l. The combination` with a hydraulic motor said work chamber devices adapted to be operated by the actuation of said switch for diverting said delivery of iiuid under pressure from said working chamber to said return chamber; a position-responsive mechanical means adapted to be actuated by the travel oi.' said ram means to a predetermined position; and devices adapted torbe operated by the actuationof said last-mentioned mechanical means for cutting oil.' the delivery of fluid to said return chamber.

34. The lcombination with a hydraulic motor 45 having reciprocable ram means; of means forming a hydraulic circuit with said motor for operating said ram means in both directions, and control means associated with said circuit for controlling the iow of uid therein to eiect completely automatic operation of said ram means, said control means including a pressure-responsiveswitch and electrical devices controlled thereby io'r automatically reversing said ram imeans upon the attainment of a predetermined pressure during the working stroke, and position-responsive means for automatically reversing said ram means upon its reaching apredetermined position during the return stroke.

A35. The combination with a hydraulic motor having reciprocable ram means; of means forming Aa hydraulic circuit `with said motor for operating said ram means in 'both directions, andk `a predetermined pressure during the working stroke, and position-responsive means for automatically reversing said ram nreans upon its reaching a `predetermined position during the return stroke.

36. The combination with a hydraulic motor 75 having reciprbcabie ram means; oi' means forming a hydraulic circuit with said motor for operating i said ram means in both directions. and cont means associated with said circuitV i'or controlling the iiow of iluid therein to eil'ect completely automatic operation of said ram means, said 4control means including electrically-operated pressure-responsive means for automatically reversing said ram means upon the attainment of tion during the return stroke.

,37. The combination with a hydraulic motor including a reciprocable' ram; of means for sup-5 plying iiuid under pressure to the motor for operating said ram: and control means associated with ,said motor including means for controlling the lo ilow of uid to said ram;' electrically-actuated pressure-responsive means for automatically et- Iecting reversal of flow to said ram upon the building up oi' a predetermined pressure on said ram during the working stroke thereof. and position-controlled means for automatically eilecting areversal oi' flow towsaid ram upon the latter's reaching a `predetermined position during the return stroke thereof.

38. The combination with a hydraulic motor including a reciprocable ram: of means for supplying'iluid under pressure to the motor for operating said ram': and controlmeans associated with said motor including means for controlling the ilow of duid to said ram; electrically-acuuted pressure-responsive means for automatically effecting reversal of ow to said ram upon the building up of a predetermined pressure on said ram during the working stroke thereof, and electricaliy-actuated position-controlled means for automatically effecting reversal of ow to said ram upon the latter's reaching a predetermined position during the return stroke thereof.

WALTER ERNST. 

